1. Field of the Invention
Aspects of the invention relate to a rechargeable battery, and more particularly to a circuit board connected to a battery, a cover case, and a battery pack using the same.
2. Description of the Related Art
Recently, compact portable electronic devices such as a cellular phone, a portable computer, a camcorder, etc., have been actively developed and manufactured. A battery pack is mounted in such portable electronic devices so they can be used in locations where a separate power supply is not available. Recently, a rechargeable battery that can be charged and discharged repeatedly has achieved widespread use because it is more economical than a non-rechargeable battery, which must be replaced when it is discharged. Examples of a rechargeable battery include a nickel-cadmium (Ni—Cd) battery, a nickel-hydrogen or nickel-metal hydride (Ni—MH) battery, a lithium (Li) battery, a lithium ion (Li-ion) battery, etc. A lithium rechargeable battery is particularly attractive because it has a higher energy density per unit weight and an operating voltage of 3.6V, which is three times higher than 1.2V operating voltage of the nickel-cadmium battery and the nickel-hydrogen battery that have usually been used as a power supply of portable electronic devices. Accordingly, the lithium rechargeable battery has become widely used as a power supply of portable electronic devices.
The lithium rechargeable battery uses lithium group oxides as a cathode active material, and a carbon material as an anode active material. Generally, lithium rechargeable batteries can be classified into liquid electrolyte batteries and polymer electrolyte batteries depending on a type of the electrolyte. The lithium ion battery uses a liquid electrolyte, and the lithium polymer battery uses a polymer electrolyte. The lithium rechargeable battery is manufactured in various shapes such as a cylindrical type, a prismatic type, and a pouch type.
Generally, in a process of fabricating the rechargeable battery, an electrode assembly is formed by laminating a cathode plate including a cathode collector on which the cathode active material is coated and to which a cathode tab is connected, an anode plate including an anode collector on which the anode active material is coated and to which an anode tab is connected, and a separator between the cathode plate and the anode plate, and winding the laminated cathode plate, separator, and anode plate to form an electrode assembly. The electrode assembly is inserted into a can type case for the rechargeable battery. Then, a bare cell is fabricated by injecting an electrolyte into the can type case, and closing the can type case with a cap assembly. The bare cell is electrically connected to a protection circuit board, and then the bare cell and the protection circuit board are put into a mold and encapsulated with a melted resin, thereby completing a resin molded type rechargeable.
However, problems may occur during the encapsulating process, such as a defective molding being formed, or the protection circuit board being twisted out of position in the completed resin molded type rechargeable battery.